Device for hoisting loads, for example antennae on towers or masts

ABSTRACT

1,157,286. Jib cranes. PHILIPS GLOEILAMPENFABBIEKEN N.V. 13 July, 1966 [13 July, 1965], No. 31503/66. Heading B8B. A derrick comprises a vertical post 1 carrying a pulley 5, a jib 2 carrying a pulley 6 and pivotally supported for luffing movement about a horizontal axis at the base of the post 1, a hoisting rope 10 passing around the pulleys and means for connecting the hoisting rope to the jib so that the rope can be used to luff the jib. The jib can be held in either its upper or lower position by either electromagnetic means or remotely controlled pawl and ratchet means. Alternatively the jib may be bolted in position. When a load 9 has been lifted into the proximity of the pulley 6, the rope is connected to the jib 2 by bolting it between a pair of clamp plates, Fig. 3 (not shown) pivoted to the jib.

Feb. 13, 1968 M. MORIHAIN 3,36

DEVICE FOR HOISTING LOADS, FOR EXAMPLE ANTENNAE ON TOWERS OR MASTS FiledJuly 8, 1966 2 Sheets-Sheet 1 INVENTOR. MARCEL MORIHAIN AG-EN I Feb.13,1968 M.MORIHAIN 3,368,695

DEVICE FOR HOISTING LOADS, FOR EXAMPLE ANTENNAE ON TOWERS OR MASTS FiledJuly 8, 1966 2 Sheets-Sheet 2 FIGS INVENTCR.

United States Patent 4,42 4 Claims. c1. 212-8) ABSTRACT OF THEDISCLOSURE A hoisting device for placing a load on a tower, such as anantenna on top of the tower having a fixed vertical arm and a swingingboom whereby one rope over the pulleys on the vertical arm and boomenables the boom to be swung to a vertical position. The latter isaccomplished by a device which temporarily connects the boom to therope.

The invention relates to a device for hoisting loads such as antennae ontop of towers or masts.

For arranging an antenna of large dimensions on top of a tower or a mastit is known to hoist the antenna first along the mast up to the topthereof, after which it is arranged at its place by tilting it; theantenna being mounted previously on the ground. The final height, theweight and the dimensions of large antennae render this tilting movementdangerous, while if the antenna is too bulky then this movement is nolonger possible. In a practical case the antenna had a length of 23meters, while side rods of about 35 meters were provided; the weight ofthe whole load was of the order of 2 tons and it had to be hoisted tothe top of a mast of 33 meters high. Such a large-size load can berigged on a mast or tower only with great difficulty.

The invention overcomes these diificulties by providing the possibilityof first hoisting the load first along the mast and of arranging itsubsequently on the top by means of a combined double translatorymovement.

The device according to the invention for hoisting loads such asantennae on top of masts or towers is characterized in that it comprisesa substantially vertical arm, provided with a pulley and secured to thetop of the mast, a boom adapted to swing in a plane bounded by thestationary arm about a shaft fastened in the proximity of the foot ofthe stationary arm, one of the ends of said boom being provided with apulley, there being provided a hoisting rope passed through the groovesof said two pulleys, the device comprising furthermore a mechanism forthe temporary connection of the boom with the rope in order to achieve aswinging movement of the boom solely by hoisting or running out therope.

The device may be employed so that, when the boom is fixed in a firstposition, the load is lifted in a first stage with the aid of the solerope, after which also by means of said rope, which is temporarilyconnected by a mechanism with said boom then released, the hoistingmovement traverses a second stage like a circular translatory movement,in which each point of the load traces substantially an arc of thecircle covered by the shaft of the pulley of the boom, while when theboom has reached a second fixed position, after the release of theconnection between the boom and the rope, the load is deposited by therope released in a third stage at the predetermined place.

The invention will be described more fully with reference to thedrawing.

FIG. 1 shows the device according to the invention in the first stage ofoperation.

3,368,695 Patented Feb. 13, 1968 "ice FIG. 2 shows said device in asecond stage of operation.

FIG. 3 shows a connecting piece employed between the first and thesecond stages.

FIG. 4 shows a variant of the part shown in FIG. 3.

FIGS. 5 to 9 show the various stages in arrangingthe load on the toweror the mast.

The device shown in FIGS. 1 and 2 is mainly formed by the combination ofa stationary arm 1 and a boom 2, adapted to pivot about a shaft 3. Thearm 1 is secured to the top of a mast 4 and is provided at its top witha pulley 5. The boom 2 is adapted to pivot on the top of the mast 4'about the shaft 3 and is provided at its end With a further pulley 6.The boom can be swung against the arm 1.

FIGS. 1 and 2 show the two extreme positions of the boom, which, in itslowermost position, has a supporting point 7 on the mast 4, and in thetopmost position, a supporting point 11 on the arm 1. The device employsa single hoisting rope 10, which extends from a winch 8 (not shown)along the pulley 5 of the arm 1 and then along the pulley 6 of the boom2.

In an advantageous embodiment the boom of the device according to theinvention is removably secured to the mast at the supporting point 7 bymeans of an electro-niagnet (not shown); this connection is improved bythe weight of the load 9, which urges the boom 2 against the support 7.Other structures using for example pawl mechanisms, which may beremote-controlled, or even bolts, in which case a mechanic is requiredto climb to the top of the mast, are also possible.

When the boom 2 is in the position shown in FIG. 1, the load 9, forexample an antenna, which is arranged vertically below the pulley 6, canbe lifted along the mast. When the load 9 arrives at the proximity ofthe pulley 6, the rope 10 is connected to the boom 2, the load remainingconnected to said rope. The electric current energizing theelectro-magnet is then switched off, so that the connection at thesupporting point 7 between the boom 2 and the mast 4 is released or theequivalent connection is disengaged. During the hoisting operation bymeans of the rope 10 the boom is lifted from the lowermost positionshown in FIG. 1 and is swung about the shaft 3 to arrive at the topmostposition shown in FIG. 2. The load connected with the boom performs atranslatory movement and is moved above the top of the mast in the axialdirection of the latter or at least perpendicularly above the finalposition.

In the position shown in FIG. 2 the boom 2 is connected for reasons ofsafety by means of a pawl mechanism (not shown) with the supportingpoint 11 of the arm 1, but it should be noted that the prevailing forcesalso tend to urge the boom 2 against the arm 1. For the same purpose,the connection may be electro-magnetic or use may be made of any otherequivalent connection. The rope 10 is then disengaged from the boom andthe load is lowered on the mast, where it is finally positioned.

FIG. 3 shows diagrammatically a first embodiment of the fasteningmechanism for the rope 10 and the boom 2. A component 12 is adapted toturn about a shaft 13, which is arranged at the side of the shaft of thepulley 6. This movable component 12 is provided with a clamping jaw 14for rigidly connecting the rope 10 with the boom 2. Any other mechanicalor electromechanical clamping means may be employed for this purpose.

FIG. 4 shows diagrammatically a variant of the connecting mechanism, theclamping jaw being omitted. A component 15 pivots at one end about ashaft 16, provided with a pawl mechanism and arranged at the side of theshaft of the pulley 6. At the other end the component 15 is provided wtha shaft 18, into which the rope 10, fastened to the load 9 can behooked. The component 15 may be provided in place before the upward 3 ordownward movement of the boom 2 and then be removed.

As shown in FIG. 3, the clamping jaw 14 holds the rope 10 and as shownin FIG. 4, the load 9 is connected with the shaft 18, which gives riseto bending forces being exerted on the component 15, the boom 2 swingingabout the shaft 3.

FIGS. 5 to 9 show more clearly how the antenna 9 is arranged in itsfinal position on top of the mast in the consecutive stages ofoperation; the movements are indicated by arrows.

The embodiments described above have to be considered as examples; itbeing understood that other variations may be possible within the scopeof the invention.

What is claimed is:

1. A hoisting device for placing a load on the top portion of a towercomprising a substantially vertical arm provided with a first pulley andfixed to said top portion of said tower, a boom adapted to swing about apivot point located in the proximate area of the foot portion of saidfixed vertical arm in a plane from at least a substantially horizontalposition to a substantially vertical position adjacent to said fixedvertical arm, the free end of said boom being provided with a secondpulley, a hoisting rope passing through said first and second pulleys,and means for temporarily connecting the boom to the rope in a fixedmanner whereby the hoisting solely of said rope results in said swingingmovement of said boom.

2. A hoisting device as claimed in claim 1 wherein said means fortemporarily connecting the boom to said rope in a fixed manner is adevice having clamping jaws, and further means including a shaftpivotally mounting said device adjacent to said second pulley.

3. A hoisting device as claimed in claim 1 wherein said means fortemporarily connecting the boom to said rope in a fixed manner is adevice provided with a shaft located adjacent to said second pulley,said device being rotatable on one end on said shaft, the other end ofsaid device being fastened to said load at a location where said loadand said rope are secured.

4. A hoisting device as claimed in claim 1 wherein said boom swings in avertical plane through approximately and the extreme positions of saidboom are determined respectively by said fixed vertical arm and thetower on which said fixed vertical arm is mounted.

References Cited UNITED STATES PATENTS 456,332 7/1891 Hitchcock 2l291,357,150 10/1920 Curtis 21258 2,051,497 8/1936 Sasgen et al. 212583,049,242 8/1962 Stevens et al. 2l258 ANDRES H. NIELSEN, PrimaryExaminer.

